Nucleobase Pair-Metal Dimer/Dinuclear Metal Cation Interaction: A Theoretical Study.

ABSTRACT: Nucleobase pair-metal dimer/dinuclear metal cation interactions play an important role in biological applications because of their highly symmetrical structures and high stabilities. In this work, we have selected five adenine-adenine hydrogen bonding, adenine-thymine (AT), adenine-uracil, adenine-adenine stacking pairs, and Watson-Crick AT stacking pairs and studied their interaction with the coinage metal dimer M2 and M2 2+ metal cations, where M = Ag, Au, and Cu. Quantum chemical calculations have been carried out with density functional theory (DFT) and time-dependent DFT (TDDFT) methods. Electronic structures were analyzed by the partial density of states method. During interactions, we find that M-M distances are shorter than the sum of van der Waals radii of the corresponding two homocoinage metal atoms, which show the existence of significant metallophilic interactions. Results indicated that nucleobase-M2 2+ complexes are stronger as compared to nucleobase-M2 complexes. Also, the replacement of the hydrogen bond by the dinuclear metal cation-coordinated bond forms more stable alternative metallo-DNA sequences in AAST base pairs. TDDFT calculations reveal that nucleobase-Cu2 complexes and nucleobase-Ag2 2+/Au2 2+ complexes can be used for fluorescent markers and logic gate applications. Atom-in-molecules analysis predicted the noncovalent interaction in these complexes.

SUBMITTER: Srivastava R 

PROVIDER: S-EPMC7408194 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature